Transcription factors instruct DNA methylation patterns in plant reproductive tissues

DNA methylation is maintained by forming self-reinforcing connections with other repressive chromatin modifications, resulting in stably silenced genes and transposons. However, these mechanisms fail to explain how new methylation patterns are generated. In Arabidopsis, CLASSY3 targets the RNA-directed DNA methylation machinery to different loci in reproductive tissues, generating distinct epigenomes via unknown mechanism(s). Here we discovered that several different REPRODUCTIVE MERISTEM (REM) transcription factors are required for methylation at CLASSY3 targets specific to anther or ovule tissues. We designate these factors as REM INSTRUCTS METHYLATION (RIMs) and demonstrate that disruption of their DNA-binding domains, or the motifs they recognize, blocks RNA-directed DNA methylation. Furthermore, we demonstrate that mis-expression of RIM12 is sufficient to initiate siRNA production at ovule targets in anthers. These findings reveal a critical role for genetic information in targeting DNA methylation in reproductive tissues, expanding our understanding of how methylation is regulated to include inputs from both genetic and epigenetic information.